ACX check

[AndyE01]

Hi there

First post! I have been recording an audio book over the last few weeks and am starting to panic about whether it will meet the submissions requirements for ACX. I've read a few posts on this forum and have applied noise reduction and used a moderate leveller. The volume sounds about right but it all seems a bit sibilant. I am worried that the quality of the original recording is not terribly good. Can anyone have a listen and let me know what they think? I am using a Yeti Blue Microphone in a home studio but keeping it well away from my laptop.

Unedited Sample.mp3

(626.33 KiB) Downloaded 150 times

Edited Sample.mp3

(626.33 KiB) Downloaded 149 times

Many thanks!

[kozikowski]

We would request postings in WAV rather than MP3. MP3 creates sound damage and you're never sure if the damage is coming from the MP3 or something the performer is doing wrong. You can post ten seconds of WAV mono on the forum. Since it's difficult to edit an existing MP3, your master archive works should all be in WAV. You can make a WAV into anything.

Very well done, but I think you're worried about the wrong things. You made the already OK noise floor much lower creating the "inky blackness of space" effect, but ignored the blue wave peaks which are too high.

Measure the peaks:
Select the whole clip by clicking just above MUTE.
Effect > Amplify. Read the top number, don't apply the tool. It should read between 3.5db and 3db.

Measure the noise:
Drag-select between 2 and 3.5 seconds.
Analyze > Contrast: Measure Selection. It should read lower noise (higher number) than 60dB. Stunning low noise values are not automatically valuable. You never had anybody reading a story to you from a black vacuum. ACX is not impressed with extreme numbers. Unusual numbers usually cause other sound problems.

Measure the Loudness (RMS)
Select the whole clip by clicking just above MUTE.
Analyze > Contrast: Measure Selection. The value range is 18dB to 23dB. This one is fuzzy and changes with the number of pauses and how theatric you are.

So that's how to measure the three numbers yourself. My opinion is you have a good enough "raw" production that it should be possible to conform to audiobook standards with very little work. Probably a good thing so you don't have to start over.......

Koz

[kozikowski]

I just went down to listen to your original noise. It's not clothing rustling or wind in the trees. It's computer whine noise similar to this:

http://kozco.com/tech/audacity/clips/Fr ... itoes3.wav

That explains why it needs to go. Is this a USB microphone or USB MicPre or other similar system?

Koz

[AndyE01]

Thanks for that Koz. It's reassuring to know I won't have to rerecord the whole thing!

I'm not quite sure I understand about the peaks. I checked the amplitude as you suggested and it says amplification 1.0 rather than between 3.5 to 3.0db. How do I alter it to get it into the right frame?

The unedited noise levels all come up within range; an average of -19.6db. The background noise is coming in at -57.2, below the -60db threshold. Does that mean I shouldn't apply any noise reduction at all? It sounds quite hissy to me.

Appreciate the help, by the way. It's a weight of my mind!

[AndyE01]

Yes, it is a USB microphone, but I use a long cable and the computer is on the other side of the room, on a different surface. How would I go about getting rid of the sound? I take it I do need some kind of noise reduction then?

[kozikowski]

I'm compiling a list of patches I would make. Yes, we get a sinking tummy feeling when somebody opens a posting with "I've been recording for six months..." I favor patches that are so gentle/wimpy they're almost seem not worth the effort, but your work is just not that far off. I could listen to that voice. Tell me all about those gales.
Koz

[AndyE01]

You're very kind! And that's the least interesting sentence in the book!

[kozikowski]

Import the unimproved clip.

Noise Reduction:
Drag-select the "silent" area between 2 and 3.5 seconds.
Effect > Noise Removal: Profile.
Select the whole clip (click just above MUTE).
Effect > Noise Removal:
— Reduction 6dB
— Sensitivity 0
— Smoothing 150
— Attack 0.15
OK

Blue Wave Peak Control:
Select the whole clip.
Effect > Normalize:
— [X] Remove DC
— [X] Normalize to -3.2dB
OK

It looks imposing written out like that, but it's only two tools and set for gentle corrections. 6dB Noise Reduction almost seems not worth the effort, but I pushed that background whine down beyond audibility.

Normalize to 3.2dB seems entirely compulsive, but it turns out that solves a WAV to MP3 conversion problem that 3.0 doesn't.

Note your voice didn't change a bit. Try the 3 tests I wrote about in that other message.

You didn't respond to my comment of doing all your work in WAV. It's all in MP3, isn't it?

Koz

[kozikowski]

The background noise is coming in at -57.2, below the -60db threshold.

That takes a bit of getting used to. Zero is maximum loudness. That's where the digital system runs out of numbers and doesn't get any louder. That's why the sound meters have -0- all the way to the right.

That makes -57.2 louder than -60. It fails.

Koz

[AndyE01]

That does sound much better. The background hum is negligible and it gets rid of the inky black effect you were talking about. Thank you for that!

I had a go at chapters one and six and did your three tests.

The contrast for the background noise is 69.6 which is good. The overall volume comes in at 25.1 for the first chapter and 26.4 for the sixth. This is a little outside the 18 to 23db range. I think the volume overall for both chapters is quieter than the average for the sample I gave you. Chapter One unedited comes in at 22.5db overall and Chapter Six comes in at 24.5db. Should I adjust the figure for "normalize" to compensate?

I am editing in Wav by the way. I recorded all the original files using Audacity so it seemed sensible. I was just a little foxed by your 2MB limit.

Andy